Package com.apple.foundationdb.map

Class BunchedTupleSerializer

java.lang.Object

com.apple.foundationdb.map.BunchedTupleSerializer

All Implemented Interfaces:

BunchedSerializer<Tuple,Tuple>

@API(EXPERIMENTAL)
public class BunchedTupleSerializer
extends Object
implements BunchedSerializer<Tuple,Tuple>

A BunchedSerializer that uses Tuples as both the expected key and value type. This uses the ability of Tuple classes to pack themselves in a fairly straightforward way. This will do the right thing, but it can be somewhat space inefficient when serializing an entry as the Tuple encoding is designed to preserve order, which is unnecessary for values.

Method Summary

Modifier and Type	Method	Description
boolean	canAppend()	Returns true.
List<Map.Entry<Tuple,Tuple>>	deserializeEntries(Tuple key, byte[] data)	Deserialize raw data to a list of entries.
Tuple	deserializeKey(byte[] data, int offset, int length)	Deserialize a slice of a byte array into a key.
static BunchedTupleSerializer	instance()	Get the serializer singleton.
byte[]	serializeEntries(List<Map.Entry<Tuple,Tuple>> entries)	Serialize an entry list to bytes.
byte[]	serializeEntry(Tuple key, Tuple value)	Serialize a pair of Tuples to bytes.
byte[]	serializeKey(Tuple key)	Serialize a Tuple to bytes.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface com.apple.foundationdb.map.BunchedSerializer

deserializeKey, deserializeKey, deserializeKeys, serializeEntry

Method Details

instance

public static BunchedTupleSerializer instance()

Get the serializer singleton.

Returns:

the BunchedTupleSerializer singleton

serializeKey

@Nonnull
public byte[] serializeKey(@Nonnull
 Tuple key)

Serialize a Tuple to bytes. This uses the standard Tuple packing function to do so.

Specified by:

serializeKey in interface BunchedSerializer<Tuple,Tuple>

Parameters:

key - key to serialize to bytes

Returns:

the serialized key

serializeEntry

@Nonnull
public byte[] serializeEntry(@Nonnull
 Tuple key,
 @Nonnull
 Tuple value)

Serialize a pair of Tuples to bytes. This packs each Tuple as nested Tuples and then returns the concatenated bytes. As canAppend() returns true, this can be used to append an element to the end of an entry list.

Specified by:

serializeEntry in interface BunchedSerializer<Tuple,Tuple>

Parameters:

key - the key of the map entry

value - the value of the map entry

Returns:

the serialized entry

serializeEntries

@Nonnull
public byte[] serializeEntries(@Nonnull
 List<Map.Entry<Tuple,Tuple>> entries)

Serialize an entry list to bytes. This will place a prefix at the beginning of the list in order to support versioning of the entry list data structure in the future. Otherwise, it concatenates serialized entries together.

Specified by:

serializeEntries in interface BunchedSerializer<Tuple,Tuple>

Parameters:

entries - the list of entries to serialize

Returns:

the serialized entry list

deserializeKey

@Nonnull
public Tuple deserializeKey(@Nonnull
 byte[] data,
 int offset,
 int length)

Description copied from interface: BunchedSerializer

Deserialize a slice of a byte array into a key. This will only deserialize the portion of the array starting at offset and going for length bytes.

Specified by:

deserializeKey in interface BunchedSerializer<Tuple,Tuple>

Parameters:

data - source data to deserialize

offset - beginning offset of serialized key (indexed from 0)

length - length of serialized key

Returns:

key deserialized from reading data

deserializeEntries

@Nonnull
public List<Map.Entry<Tuple,Tuple>> deserializeEntries(@Nonnull
 Tuple key,
 @Nonnull
 byte[] data)

Description copied from interface: BunchedSerializer

Deserialize raw data to a list of entries. This should be the inverse of serializeEntries. Note that the order of elements returned within the list should be the same as their sort order. The key that this entry list is stored under is passed in so that implementations that wish to can choose to omit the first key of the entry list from the serialized value.

Specified by:

deserializeEntries in interface BunchedSerializer<Tuple,Tuple>

Parameters:

key - key under which the serialized entry list was stored

data - source list to deserialize

Returns:

entry list deserialized from reading data

canAppend

public boolean canAppend()

Returns true. This format supports appending serialized entries to the end of a serialized entry list to create the serialized bytes of the original list with the new entry at the end.

Specified by:

canAppend in interface BunchedSerializer<Tuple,Tuple>

Returns:

true as this serialization format supports appending